Figure 2

Exogenous galanin attenuates cooling responses. [A] Digitised trace of recording of subcutaneous skin temperature of the dorsal surface of the rat hindpaw. Room temperature saline did not alter skin temperature. Application of acetone led to a reduction in skin temperature. This returned to normal within 100 seconds. A second application of acetone again resulted in a similar drop in temperature. [B] Acetone application to the receptive field of an identified cooling sensitive primary afferent led to a significant increase in neuronal firing, which was significantly greater than the control application of room temperature saline (**p < 0.01 one way ANOVA with post-hoc Bonferroni test, n = 6). Cooling evoked activity was significantly inhibited following administration of c.i.a. 100 μM galanin (*p < 0.05 Paired t-test, n = 6). [C] Example trace of an acetone/cooling sensitive C fibre in response to room temperature saline. [D] Example trace of an acetone/cooling sensitive C fibre. [E] Acetone evoked activity was attenuated in the same C fibre by c.i.a. 100 μM galanin. AP = action potential, AP number events = total number of action potentials occurring per second.